Drugs reducing the electrical restitution slope to <1 (diacetyl monoxime and verapamil) prevented VF induction and converted existing VF into a periodic rhythm in canine ventricles.
Does reducing the slope of the electrical restitution relation with diacetyl monoxime or verapamil prevent the induction of ventricular fibrillation in a canine model?
Reducing the slope of the electrical restitution relation prevents the induction and maintenance of ventricular fibrillation in a canine model, suggesting a novel mechanistic approach to antiarrhythmic therapy.
Despite recent advances in our understanding of the mechanism for ventricular fibrillation (VF), important electrophysiological aspects of the development of VF still are poorly defined. It has been suggested that the onset of VF involves the disintegration of a single spiral wave into many self-perpetuating waves. It has been further suggested that such a process requires that the slope of the electrical restitution relation be >/=1. The same theory anticipates that a single spiral wave will be stable (not disintegrate) if the maximum slope of the restitution relation is /=1 in canine ventricle. We now show that drugs that reduce the slope of the restitution relation (diacetyl monoxime and verapamil) prevent the induction of VF and convert existing VF into a periodic rhythm. In contrast, a drug that does not reduce the slope of the restitution relation (procainamide) does not prevent the induction of VF, nor does it regularize VF. These results indicate that the kinetics of electrical restitution is a key determinant of VF. Moreover, they suggest novel approaches to preventing the induction or maintenance of VF.
Riccio et al. (1999) studied Ventricular fibrillation. Diacetyl monoxime and verapamil vs. Procainamide was evaluated on Induction and maintenance of ventricular fibrillation. Drugs reducing the electrical restitution slope to <1 (diacetyl monoxime and verapamil) prevented VF induction and converted existing VF into a periodic rhythm in canine ventricles.